Fig. 3: Correlating FEM-based stress response with experimental validation of unimodal particle size effects.
a Frequency distribution of unimodal SiO2 particles with nominal diameters of 0, 1.5, 10, and 20 µm, measured using a laser-scattering PSD analyzer. b SS curves for different SiO2 particle sizes. The blue area indicates the target fibrillation region, and the gray area represents the failure region leading to film-like deformation. The circle and square symbols on the SS curve denote the yield point and the onset of fibrillation, respectively. c Cohesive-strength test results. SEM images of samples containing SiO2 particles with sizes of d 20, e 10, f 1.5, and g 0.1 μm. h Mercury intrusion porosimetry results for dry electrodes prepared with unimodal SiO2 particles of different median sizes. Reliable porosity measurement for the dry electrode fabricated with 0.1-µm SiO2 particles was impossible owing to its brittle nature. i–k Schematic of the effect of the particle size on the PTFE deformation behavior. i Film-like deformation. j Fibrillation. k Insufficient fibrillation.
